Air cleaner



SGPL 17 l940- R. c. DARNELL Re- 21,570

AIR CLEANER Original Filed Jan. 26. 1938 lllllll- 3 Pmanhqc of Chmn, Effici un,

Pgrcenlqge 0f Mawr, Enqina Lan( F1315. Rw C. m22@ ATTORNEY. 5

nsamassptir, 1940 AIB CLEANER Rex C. Darnell, Detroit, Mich., assignor. by menne to. to King-Seeley Corporation, Ann Arbor, Mich., a corporation oi' Michigan d Original N0.'2,l59,55l, dated May 23, 1939, Serial N0. 136,910, January 28, 1938.

Application for reissue July 29, 1939, Serial No. 287,335

9Claims.

This invention relates to air cleaners, and has to do particularly with an air cleaner for use with engines of the internal combustion type.

The invention is directed particularly to the provision of an air cleaner for use with engines used in tractors, trucks, or in other installations, either stationary or mobile. although, of course,

the invention may be employed with passenger vehicles.

Among the objects of the invention is the provision of an air cleaner ofthe oil bath type and which involves improvements, by means of which a high cleaning eillciency is obtained, while the physical dimensions of the cleaner are minimized and at the same time a high factor of safety is obtained against pulling the oil therein over into the engine. Further, the inventionaims to provide a illter wherein the filtering element is selfcleaning and the dirt is caught and conned in a body of oil, in connection with which adequate provision is made in a primary oil volume for retaining the accumulated dirt. In this connection the quantity of oil used in the cleaner is separated in what may be termed primary and secondary portions or bodies, to the end that a body of oil wherein the dirt and other extraneous matter is collected is more or less quiescent during engine operation, and the accumulated material is not agitated or caused to move again into the filtering element. Still further, it is the aim of the invention to provide an air iilter wherein a broad range of oil levels may be used without materially interfering with the function and eiliciency of the cleaner.

In a static condition, the oil is retained in a receptacle below the illtering medium. 'I'he receptacle is so partitioned that a portion of the oil is positioned in the path of the air stream and is subject to being carried into the illtering element. The arrangement is preferably such that even if all this portion of oil is carried into the illtering element, the quantity does not exceed that which would cause'the oli to pull through the element and over into the engine.

'Ihe partition which defines the above mentioned portion of oil is not entirely closed so that the surface of the remaining oil is exposed to the air stream preferably at about the time the air stream turns to move upwardly into the flltering element. Thus extraneous particles are disposed in the remaining oil in the receptacle. The partition means is so arranged that some oil which has been drawn into the iiltering element may drain back into that portion of the receptacle which contains oil not subject to being carried into the iiltering element by the air stream. Thus the remaining oil in the receptacle has a surface with which the air stream makes contact and a surface underlying and in communication with the illtering medium. In order to prevent 5 air from flowing through the body of oil which remains in the receptacle. in which action the air may carry some additional oil with it into the filtering element, the receptacle is further divided by a partition or mask plate, which prevents the 10 air from passing through the receptacle inthis manner. Thus the receptacle is substantially divided'into three oil-containing compartments.

In the accompanying drawing one construction is shown for carrying out the invention, and also 16 some charts are illustrated to demonstrate the function and emciency of the cleaner.

Fig.. 1 is a vertical section taken through a cleaner constructed in accordance with the invention. 20

Fig. 2 is a sectional view taken substantially on line 2-2 of Fig. 1.

Fig. 3 is a partial sectional view similar to Fig. 1 but showing a condition of operation.

Fig. 4 shows acurve illustrating a quantity of 25 oil retained in the filtering element at various engine loads.'VV

Fig. 5 is a similar chart showing the curve of a cleaner of a type heretofore known.

Fig. 6 shows an eiliciency curve of the cleaner 30 oi this invention.

Fig. 7 illustrates an emciency curve-of a cleaner of th5e type having the saturation curve shown in Fig.

'I'he cleaner may advantageously take the form 35 of a cylindrically shaped body disposed on a vertical axis. It has an exterior shell I with a top closure 2. An air inlet tube 3 extends through the closure 2 and terminates below a illterlng element l which is disposed within the shell i and 40 around the inlet tube 3. l 'I'he filtering element may be conilned in its upper end by a foraminated element 5 which may be of screen construction or sheet metal formation with apertures therein. At the lower end the filtering ele- 45 ment is defined arid supported by a foraminous element 6 which likewise may be of screen construction or apertured sheet metal construction, and the elements 5 and 6 may be flanged and secured to the tube 3 as at 'l and 8. 'Ihe upper por- 50 tion of the element terminates below the closure 2 to provide a chamber 9, from which leads an outlet or conduit I0 which may be connected with the inlet manifold or carburetor of the engine. I'he member 6 preferably is shaped to give 55 the lower end of the nltering element a frustoconical shape with the lower portion thereof surrounding the tube 3 extending downwardly toward the oil sump, as will presently be described.

An oil receptacle or sump Il may be telescoped over the lower end of the shell and may be held in position by bolts I0 and a strap or support Il underlying the sump. The lower edge of the shell may be provided with a ange Il while the receptacle I l may be equipped with a shoulder Il. An oil cup 2l may be disposed within the receptacle II and it may be fashioned from sheet metal with an outwardly extending flange at its upper end which lies upon the shoulder I! and is clamped in position between the shoulder It and the nange Il. The flange on the oil cup is illustrated at 2| and it is cut out to provide apertures 22. 'I'he circumferential wall of the cup 2l in the upper regions may be substantially cylindrical, as shown. while the lower portion is downwardly and inwardly inclined as at 23,y and the cup terminates in a central opening 24. An element which may be termed a mask plate or partition is illustrated at 2B. 'I'his may be an imperforate sheet metal plate secured tothe oil cup as by means of fashioning the metal around the opening 24 over the edges of the mask plate as illustrated at 2l, and the mask plate may have a peripheral flange 21 arranged for a nice sliding nt within the receptacle Il.

The oil cup is provided with a series of oil flow apertures 3l located preferably above the inclined bottom walls 22 and below the normal liquid level which is illustrated at A.

The cup 2l deiines an air passageway Il which is circumferential in form around the lower end of the tube I, and it divides the receptacle in that the cup forms the passageway 2| on the inside and a chamber I2 on the outside thereof. The bottom of the chamber 32 is dened by the mask plate 2l, and below the mask plate is a chamber 23 for containing a body of the cleaning oil. The volume of oil above the mask plate. including that oil within the cup when the cleaner is in a static condition, and in the chamber 22, may be termed the secondary volume or body of oil, whereas the oil in the chamber 22 may be termed the primary body of oil. In some of the claims appended hereto the oil in the cup 2l, the oil in the chamber Il, and the oil in the chamber 22 are termed first, second and third bodies of oil, respectively.v

In general. the operation is as follows: As the engine creates a partial vacuum in the connection Il, air from the outside is caused to iiow in through the tube I. thence into the cup 2l as illustrated by the arrows in Fig. 3, thence upwardLv' into the iiltering medimn l. The chamber 32 is out of the air iiow, and therefore the portion of the filtering medium overlying this chamber is more or less in what may be called a quiescent zione. 'I'he upper edge of the cup 2| preferably comes into close proximity or in contact with the element i at about the point X, although a working clearance may be provided at this point. The oil which is carried from the cup upwardly into the filter may iiow or migrate to the outer sone of the filtering medium over the chamber I2 and more or less out of the air stream, and therefore may flow by gravity back down into the compartment 22 through the apertures 22. Thisbuilds up a head of oil in the compartment 32 so that oil is caused to ow back into the cup through the holes Il` where this oil is picked up by the air stream and again lifted into the filtering medium. In much of the engine operation the bottom of the cup 32 may be substantially devoid of oil, and the air moving downwardly from the tube 2 may strike the surface of the body of oil in the chamber 22 at the location of the aperture 24. 'I'his is the general operation, and specinc points follow.

It will be noted that the air stream makes an abrupt reversal of direction within the cup 2l. Many of the larger bodies of dirt and extraneous matter will be deposited on the oily surfaces of the inclined bottom of the cup while some of the larger particles will nave a direct impact with the surface of the oil at the opening 24 and will be retained. 'I'he larger particles striking the inclined surfaces will gravitate down the surfaces and fall into the primary body of oil. Most of the dirt will be separated from the air in this manner, particularly the larger particles. 'Ihe body of oil in'the chamber 3l is substantially quiescent in that it is not in an air iiow stream and therefore a large quantity of dirt may be retained in the compartment 22 and will in no way interfere with the circulation of the secondary oil, which circulation is from the cup into the filtering medium back into the chamber 22 and thence back into the cup through the apertures Il.

'Ihe remaining particles follow the air stream and move up into the ltering medium, but the oil which is picked `up by the air wets these particles and retains them. This oil then iiows back into the chamber 32. as above described. and the dirt and particles carried therewith may settle at the bottom of the chamber I2 which is on the mask plate 25. Therefore, it will be seen that the accumulated dirt is outside of the cup. and even though a large quantity is accumulated in the chamber 32 or chamber 22, the oil in the cup may be substantially free of any such accumulation. Therefore, the ow of air through the cleaner is not restricted by accumulated dirt. The ltering element is self-cleaning in that oil moves in a circuitous path into and out of the element. In other words, assuming a condition where there is a constant nowv of air through the cleaner, the secondary volume of oil moves in a circuitous path constantly removing the dirt fro the filtering medium. v a

The use of the mask plate permits of locating the bottom of the cup 20, and therefore opening 2l, in relative close proximity to the inlet tube. This factor, therefore, contributes to the minlrnizing ot the physical dimensions of the cleaner. In other words, the cleaner can be made shorter. This is an important item since, as a rule, a cleaner has to be installed in any available space in or around the engine.

'I'he eiliciency of an oil bath cleaner depends very largely upon the amount of oil retained in the ltering medium. -Of course, whatever oil enters the filtering medium has been carried into the same by the air passing through the iilter. Heretofore at relatively low engine loads the amount of oil in the iiltering medium was relatively low and the oil in the ltering medium did not approach its maximum volume until the engine was operating at maximum load. The result was low eillciency at low engine loads. With the arrangement oi' this invention substantially all of the oil in the cup 2li is lifted into the ltering medium at relatively low engine speeds, and likewise at relatively low engine loads.

As the speed of the engine or load increases, 'Il

however, the volume of oil in the nltering medium does not substantially increase, and therefore there is little likelihood of pulling the oil completely through the filter and over into the engine. Therefore, the invention makes it feasible to shorten the over-all dimensions of the nltering medium, and this contributes to minimixing the physical dimensions of the lter.

Fig. 4 shows a curve found by test of a filter constructed in accordance with this invention, showing the oil in the filtering medium at various engine loads. At zero load, or in other words with the engine idling and not under load, there was almost an ounce of oil in the filtering medium. At about engine load three ounces of oil was in the medium, and from 50% of engine load 4to 100% of engine load the increase was very slight with the obvious indication that \the filtering medium was substantially saturated at all loads above 50% of maximum engine load. The cup 20 is substantially devoid of oil at this time. Note particularly the abrupt rise in the curve from about 20% of engine load to 45% of engine load. By way of comparison the curve shown in Fig. 5 may be considered. The same capacity filter was used in a test to determine the curve shown in Fig. 5, but the mask plate was not used and, therefore, the oil was not divided into primary and secondary bodies. VAt

zero engine load there was only a small :fractionV of an ounce of oil in the medium, and even at 70% of maximum engine load the oil in the medium had only reached one ounce. From '10% to 100% engine load, however, the curve rises relatively abruptly to something over three ounces.

'I'his means that the cleaning eiiiciency of a cleaner using the mask plate is much higher at all speeds under maximum engine load than a iilter using no mask plate. The efciency curve of the present lter is shown in liig. 6, and it will be noted that even at zero engine load the efiiciency was 99.6%, rising substantially to 99.8 at about 80% of engine load. 'I'he eiciency curve of the filter which was used in the ascertaining of the saturation curve shown in Fig. 5 was 98.2 at zero engine load and the efliciency curve more or less follows the nature of the saturation curve shown in Fig. 5. Therefore, it will be seen that the present filter not only has a much higher efiiciency starting from no engine load, but substantially reaches maximum eiiiciency at about of engine load as against a lter which does not reach its maximum efiiciency until maximum engine load is reached.

The improved eiiiciency of this cleaner isA greater than one might ordinarily think by considering the efliciency curves in Figs. 6 and 7. The curve in Fig. "l is that of a cleaner without a mask plate. Take, for example, the relative cleaning emciencies at zero load. The improved cleaner allowed .4% of the dirt content to enter the engine, while the other cleaner passed 1.8%. Therefore, the cleaner of less efiiciency passed four and a half times as ymuch dirt as did the cleaner of the present invention. Therefore, while the actual percentage in figures does not immediately appear to be remarkably different, yet there is this remarkable difference when the actual relationship of the amount of material passed through the cleaner is considered. Improving the efciency of the cleaner from such relatively high points of efficiency represents a real contribution to the art.

As tothe broad range of oil levels which may be used, it may be pointed out that if the level is increased above the level A in Fig. 1, that much of this oil is isolated in the upper portion of the chamber l2. Therefore, a considerable increase in oil level will not cause the oil to pull over into the engine because of this isolation of a considerable percentage of the oil. In one illter which has been made and used, 32% of the oil was thus isolated, although, of course, this would vary with diil'erent dimensions. Also,`the lter may be operated with an oil level below level A, the point being that the filtering medium extends down relatively close to the oil level, due to the frusto- If the oil reaches the lower portion of the lter which, in the form illustrated, happens to be adjacent the tube I, the oil easily iiows through the interstices of the iilter and thence into the quiescent zone andr back into the chamber 32. By having a iilter which will operate over a large diii'erential of oil levels, the filter will function properly even though a mechanic is careless in adjusting the oil level after cleaning or when the oil level is raised after long usage due to accumulated dirt.

To clean the iilter the receptacle I5 is taken off and the cup and mask plate may then be removed and parts restored with a quantity of clean oil. Throughout this specification and in the claims the cleaning liquid is referred to as oil,

as this is the usual liquid used, although it is to be understood that the invention is not limited to a liquid strictly known as oil, as this cleaner may be used with any suitable cleaning liquid, oil, or otherwise.

. The mask plate positively prevents flow of air through the aperture 24 and up into the filtering medium in the space surrounding the cup 20. At high speeds air may tend to iiow through this path, but is positively prevented from doing so. This isa factor in preventing pulling oil completely through the iiltering medium at high speeds and over into the engine, since the only air and oil to enter the filtering medium is that flowing through the passageway 3|.

In the form of the invention shown, there is a circulation'of oil from within the cup 23 to the lter, `then back into the chamber 32, thence into thecup through the apertures I0. The cleaner may be arranged to have this circuitous movement of the oil during engine operation. On the other hand, the cleaner maybe arranged so that the oil which is lifted into the filter substantially remains therein during engine operation and iiows back into the receptacle upor. cessation of engine operation. 'I'he use of the terms primary and secondary are not intended to serve as limitations, but are intended merely as handy terms for descriptive purposes.

I claim: 1. An air cleaner comprising a casing having 'an air inlet, a iiltering medium and an air outlet, said casing including a receptacle for oil forming a closed connection between `the inlet and the filtering medium; a cup in the receptacle into which the inlet opens, the walls of the cup being spaced from the walls of the receptacle and the inlet to dee spaces inside the cup and outside and around the cup adjacent the filtering medium, said walls of the cup having apertures therein, the bottom of the cup having an aperture therein in substantial alignment with the air inlet, and a partition member bridging the spacebetweenthecupandthewallsoithere-v ceptacle for dividing the receptacle into two` main oil containing compartments.

3.an`aircleaneroompriaingacasinghaving 6 an airinlet, a iiltering medium, an air outlet and a receptacle for oil forming a closed connection between the inlet and the filtering medium, said inlet extending into the receptacle, a cup in the receptacle the walls oi' which surround the air inlet in spaced relation thereto and denning an air iiow passage, the walls ot the cup being spaced from the walls the receptacle deiining a chamber outside and around the cup, the walls of said cup having apertures therein forming a ccmmunication between the chamber and the interior of the cup, the bottom of the cup having an aperture therein in substantial alignment with the air inlet. and a partition located substantially at the bottom of the cup and extending from the cup to the side walls of the recepacle for dividing the receptacle into two oil compartments, one on each side of the partition connected at said aperture in the bottom of the cup.

3. An air cleaner comprising a casing having an air iiltering medium therein, a receptacle for oil below the illterlng medium. an inlet tube extending through the medium and opening into the receptacle, an outlet for air above the flltering medium, a cup in the receptacle into which the inlet tube opens, the walls of the cup being spaced from the inlet tube and the receptacle to definean air ow passageway inside the cup leading to the medium and a quiescent chamber outside and around the cup, the walls of the cup having apertures therein connecting the air iiow passageway and the quiescent chamber, the bottom of the cup being spaced above the bottom of the receptacle and having an opening therein in substantial alignment with the inlet tube. and a partition extending substantially from the bottom ci the cup to the side walls of the receptacle.

4. An air cleaner comprising a casing having an air illtering medium therein, a receptacle for oil below the iiltering medium, an inlet tube ex- 4| tending through the medium and opening into the receptacle. an outlet for air above the filtering medium, a cup in the receptacle into which the inlet tube opens, the walls of the cup being spaced from the inlet tube and the receptacle to l deiine an air iiow eway inside the cup leading to the medium and a quiescent chamber outside and around the cup, the walls of the cup having apertures therein connecting the air iiow eway and the quiescent chamber, the bottom of the cup being inclined away from the inlet tube toward the center of the cup and having an` opening positioned in substantial alignment with the inlet tube, the bottom oi the cup and opening being spaced above the bottom oi the receptacle, and a partition extending substantially from the bottom oi the cup to the side walls of the receptacle i'or dividing the receptacle into a lower and upper compartment i'or oil communicating with each other at said opening in the bottom o! the cup.

5. An air cleaner comprising a shell including a receptacle in its lower portion for containing a quantity of oil, a ltering medium in the shell spaced above the static oil level, an air inlet tube extending through the shell and having its inner end disposed below the static level of the oil, an air outlet above the filtering medium, a cup in the receptacle having walls surrounding the lower end of the tube in spaced relation for dennlng an u aireway,thewallsoithe cupbeingspaced from the walls of the receptacle to deilne a quiescent chamber outside the cup which communicates with a portion o'i the filtering medium, the side walls of the cup having apertures therein connecting the quiescent chamber with the air l ilow passageway, the bottom oi' the cup being inclined downwardly toward its center and being spaced irom the bottom of the receptacle, the bottom of the cup having an aperture therein in substantial alignment with theinlet tube, and a partition plate extending from the cup to the walls of the receptacle ior dividing the oil therein into two bodies, one positioned below the partition and one positioned above the partition, with the body above the partition including the oil within the cup and the oil in the quiescent chamber. l

6. An air cleaner comprising a casing having a illtering medium therein, and air inlet tube extending through the casing and ltering medium and opening at its lower end. an air outlet above the filtering medium, a receptacle at the lower end oi' the casing i'or containing a quantity of oil, a partition extending across the receptacle positioned above the bottom of the receptacle and below the lower end of the inlet tube i'or dividing the oil into upper and lower bodies, said partition having an opening in substantial alignment with the inlet tube forming a connection between the two bodies of oil, and means above the partition for dividing the space between the partition and the lower end oi' the iiltering medium into an air passageway and into a quiescent zone, said quiescent zone being in communication with the ltering medium, said means having apertures therein positioned below the static oil level and connecting the quiescent chamber and air tlow passageway.

'1. An air cleaner comprising a casing, an air illtering element therein, a receptacle i'or containing a body of oil below the illtering medium with the static level normally spaced below the lower end oi' the ltering medium, an air inlet tube extending through the casing and opening into the receptacle, air outlet means above the iiltering medium, means in the receptacle for dividing the oil into upper and lower oil bodies, said means lying abovethe bottom of the receptacle and having an opening in substantial alignment with the open end of the inlet tube, and means for dividing the portion of the receptacle above the partition into an air passageway leading from the inlet tube to the Vfiltering medium and into a quiescent zone in communication with the ltering medium, said means having eways for connecting the quiescent zone with the air eway whereby to provide a circuitous ilow path for the oil above the partition'. to-wit, from the air passageway into the filtering medium, thence into the quiescent zone and back into the air passageway 8. An air cleaner comprising a vessel for con- -`taining a quantity of oil, a filtering element disposed above the oil, an air inlet passageway leading to below the element, air outlet means connecting above the element, partition means extending into the vessel and dening on one side thereof a rst body of oil having its static surface substantially directly in the path of the air and in such proximity to the iiltering element as to be substantially all carried into the filtering element, said filtering element having the capacity to hold all the oil in the rst body without overflow, a substantially imperiorate partition below the static level of the oil dividing the oil on the oppou site side of the partition means into second and third bodies, the static surfaces of the rst and third bodies being exposed to the space below the filtering element, and the rst and second bodies being in communication with each other below the static level, said partition means having one or more ports therein for equalizing of the static level in the first and third bodies, the substantially imperforate partition closing the vessel against air ow through the second and third bodies oi' oil.

9. An air cleaner comprising, a vessel for containing a quantity of oil, a filtering element above the oil, an air inlet passageway leading to below the element. air outlet means connecting above the element. means for dividing the oil substantially into three bodies, the iirst oi' which has its static surface in the path of the air and in such proximity to the filtering element as to be substantially all carried into the filtering element, the second of which communicates with the first below the static level and the third o1' which has 6 its surface underlying the iiltering medium for the drainage of oil from the filtering medium to the third body, said filtering element having the capacity to hold all the oil in the first body without overflow, said means including a substantially imperi'orate partition between the second and third bodies and below the static level of the oil to prevent ow oi' air therethrough, and one or more passages in the dividing means for the equalizing o! the static level of the first and third bodies.

REX C. DARNELL. 

